3 Answers
3

Nature has designed some food-stuff to last a long time. Grains (wheat, rice, corn, oats, ...), which are the seeds of grasses, will last the longest, often more than one year. Seeds need a long shelf-life if the plant is going to make it to the next growing season. Next come roots (onions, potatoes, ...), which need to last from one year to the next. Nuts, in the cooking sense, are seeds surrounded by a shell, will also last several years if they are dry. So almonds, peanuts, pine nuts will keep, but not coconuts or chestnuts. Other food types are going to need some help, which basically means getting rid of the water in the food-stuff (lentils, beans, peas, chick peas, soybean, ...) or slowing down bacterial growth (through dehydration, freezing, irradiation, canning, cooling, ...)

I have cooked grains and dried beans and lentils from my pantry that were over a year old. They all made good meals.

Most root vegetables will last a good while: potatoes, carrots, turnips. Onions, horseradish and garlic, with their astringent properties, last a very long time.

Apples used to be preserved by packing them in barrels with water, but the phrase "one bad apple spoils the bunch" is wholly accurate. They last better where it's cool and damp. Likewise oranges and grapefruit. The less the fruit touches the better. With fruit, the best you can hope for is 4-6 months.

Harder varieties of squash last for months and months, in cool temperatures.

If you need things to last a year, I'd look into drying and/or canning. Pack fruit in sugar to leech out the water, and it'll last a year or more.

Onions will last a year as long as they are kept dry. My parents have a wire mesh rack suspended from the garage ceiling and they put the onions up there after harvesting them. Make sure none are touching each other, and although a couple might go bad the rest will be fine for a year.